A logical move, preparing the development of the knight on a3, but it's not clear how White will react when Black plays a7-a6. It seems to me that both players confused the move order in the opening, which is not surprising; after all, this is a blitz game.
8... c6e5  9. d4e5  9... d8c7  10. c1f4 The fourth most popular move. Nepomniachtchi, as do all elite players, has his own views on opening theory. 10... g8e7 